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WHOOP 4.0 vs. 3.0: What’s New With the 4.0?

September 19, 2021

From a smaller design and new features, to a state-of-the-art line of apparel that lets you wear WHOOP all over your body, we look at what’s new with the WHOOP 4.0 and break down key differences between the 4.0 and 3.0.


The next generation of WHOOP is here! WHOOP 4.0 is smaller, smarter, and combines our cutting-edge technology with an upgraded design, advanced coaching, and all-new health monitoring.

Below we’ll dive into everything that’s new with the 4.0. We break it all down into three categories: Hardware, Software, and Any-Wear.


Hardware: New WHOOP 4.0 Design

Smaller Size

The WHOOP 4.0 is 33% smaller than the 3.0, so it takes up significantly less real estate on your wrist (or elsewhere–more on that to follow). Even with the decrease in size, the 4.0 still has the same 5-day battery life as the 3.0.

whoop 4.0 sensor vs 3.0

The WHOOP 4.0 is two-thirds the size of the 3.0.

Enhanced Sensor Configuration

WHOOP 4.0 has four times the number of photodiodes on the sensor and five LEDs that use green, red, and infrared light for new metrics and increased data accuracy.

whoop 4.0 sensor and LEDs

The WHOOP 4.0 sensor has 5 LEDs (that use 3 different wavelengths of light) and 4 photodiodes.

Haptic Feedback

A feat of engineering given the new smaller size, the WHOOP 4.0 includes a spinning motor that creates vibrations to provide haptic alerts and take our Sleep Coach to the next level.

Next-Generation Battery Technology

While adding new hardware components and simultaneously cutting down the size, we needed to improve the battery in order to maintain its ability to last five days without charging. WHOOP 4.0 is the first product worldwide powered with Sila’s silicon anode battery materials, which deliver 17% higher energy density than the 3.0.

Smarter Waterproof Battery Pack

Also smaller than its predecessor, the 4.0 battery pack is waterproof and wearable. Double tap to how much power it has remaining, single tap to save battery pack power, and adjust your battery pack LED brightness whenever you need. With up to a 5-day battery life, you can keep your WHOOP always on.

whoop 4.0 waterproof battery pack

The WHOOP 4.0 comes with a waterproof wireless charger.


Software: New WHOOP 4.0 Features and Metrics

Pulse Oximeter & Blood Oxygen Levels

With its new LED configuration, the WHOOP 4.0 now has the ability to monitor blood oxygen levels (SpO2) with pulse oximetry. Although most common pulse oximeters track this from your finger, the WHOOP 4.0 uses the same technology to calculate it on your wrist.

Learn More: New WHOOP 4.0 Metric – Blood Oxygen Monitoring

Skin Temperature

The WHOOP 4.0 is equipped with a skin temperature sensor to provide you with another layer of knowledge regarding your body’s readiness to perform. It builds a personalized baseline for your own skin temp and alerts you to any daily variations.

Learn More: New WHOOP 4.0 Metric – Skin Temperature

Health Monitor

Along with the two new metrics listed above (SpO2 and skin temperature), the 4.0’s Health Monitor feature displays your live heart rate, resting heart rate, heart rate variability, and respiratory rate, providing key vitals all in a single place.

whoop 4.0 health monitor screenshot

The WHOOP Health Monitor displays key physiological metrics and alerts you to changes outside your typical baseline range.

If any of these stats stray too far from your normal baseline range, the Health Monitor lets you know via a color-coded system (green, orange, red) that something could be amiss. Additionally, the Health Monitor creates downloadable PDFs of 30-day and 180-day trend reports which you can share with your trainer, coach, or physician.

Learn More: New WHOOP 4.0 Feature – The Health Monitor

Sleep Coach with Haptic Alerts

With the WHOOP 4.0 now capable of sending haptic alerts, we gave the Sleep Coach a major upgrade. It now includes three alarm settings to silently and gently wake you depending on your sleep needs–at a specific time of your choice, when you’ve reached a desired sleep goal, or when your recovery is green.

whoop 4.0 haptic alarm options

The WHOOP 4.0 sleep coach with haptic Alerts can wake you at an exact time, based on your sleep goal, or when your recovery is green.

Learn More: New WHOOP 4.0 Feature – Sleep Coach with Haptic Alerts


Any-Wear: WHOOP Body & Bands

WHOOP Body Featuring Any-Wear Technology

The first step in making wearables invisible, WHOOP Body with Any-Wear Technology redefines what they can be by enabling you to wear your WHOOP 4.0 in a variety of different places on your body.

whoop body sports bra 4.0

WHOOP Body apparel lets you wear your 4.0 in a variety of places besides your wrist.

We’re releasing two WHOOP Body apparel collections:

  • The Training Collection features sports bras, compression tops, leggings, shorts, and athletic boxers
  • The Intimates Collection also includes bralettes and everyday boxers

Within each WHOOP Body garment there is a discrete pod that the WHOOP 4.0 sensor effortlessly slides into to seamlessly capture all your data away from the wrist.

whoop body sensor and pod

Each piece of WHOOP Body apparel has a pod to securely hold your 4.0.

Learn More: WHOOP Body – Introducing the Future of Wearable Technology

SuperKnit Bands

The WHOOP 4.0 comes with our new SuperKnit band, constructed for ultimate durability and comfort. SuperKnits are available in dozens of colors and are pre-threaded (see why below).

Fast Link Slider

The 4.0’s new Fast Link system makes it easier than ever to change your bands, or remove the sensor to place it in your WHOOP Body apparel. Fast Link lets you quickly slide bands on and off without having to adjust the threading.

superknit band with fast link

The WHOOP 4.0 features a new superknit band and fast link slider to easily remove it from the sensor.


New Membership Option: WHOOP Pro

As with the 3.0, the WHOOP 4.0 comes free with your membership. However, with the launch of the 4.0 we’re also offering a new membership option called WHOOP Pro. For an additional $12 per month (or €12/£12) the WHOOP Pro add-on gets you 20% off WHOOP Store items as well as free shipping and returns on every purchase, early access to new releases, and one free accessory item per quarter–every three months you’ll have your choice of free band, battery pack, WHOOP Body apparel, WHOOP Pro gear, and more!


The products and services of WHOOP are not medical devices, are not intended to diagnose COVID-19, the flu or any other disease, and should not be used as a substitute for professional medical advice, diagnosis or treatment. All content available through the products and services of WHOOP is for general informational purposes only.


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